Anodizing rack and method of making same



April 6, 1965 E. B. ROSNER ANODIZING BACK AND METHOD OF MAKING SAME 2Sheets-Sheet 1 Filed Dec. 17, 1962 as INVENTOR:

ERNEST B. ROSNER BY [W ATT Y5 April 6, 1965 E. B. ROSNER 3,176,850

ANODIZING RACK AND METHOD OF MAKING SAME Filed Dec. 17, 1962 2Sheets-Sheet 2 IN VENTOR:

ERNEST B. ROSNER ATT'YS 3,176,850 ANODIZING RACK AND WTHOD F MAKENGear/m Ernest B. Rosner, 194 N. Green St., @hicago, lill. Filed Dec. 17,1962, Ser. No. 244,982

Claims. (til. ZlL-lIW) This invention relates in general to rackstructures for supporting articles during plating and like processes andin particular to a novel adjustable rack structure which is ideallysuited for use in the process of anodization of articles of varyingsizes and dimensions. This invention also relates to the method ofmanufacture of such a racl; structure. This invention is an improvementon the anodizing rack shown and described in my US. Patent No.3,033,776, issued May 8, 1962, and entitled Anodizing Rack. r

The process of anodization is quite different from the general processof electroplating and rack structures used for the electroplatingprocess are normally unsuitable for the anodization process.

In ordinary electroplating processes, two dissimilar metals are used asan anode and a cathode, respectively, and metal is transferred from theanode to the cathode by well-known electrolytic action. The articlesbeing electroplated are the cathode electrode and may be any of a widevariety of metals. The rack structure for supporting these articles inthe chemical bath is a part of the cathode and may be of a metaldifierent than the article being electroplated as long as it hassufficient capacity to carry adequate electroplating current.

In the anodization process a current is passed through an acid bath andthrough the immersed article being anodized causing the formation of anoxide layer on the article. Since the supporting rack for articles beinganodized will be partially or Whollyimmersed, an oxide layer will beformed on the rack also. The oxides of both the rack and the articlesbeing anodized should be compatible with the bath solution being used.This requires a supporting rack fabricated from a metal havingsufiicient current carrying capacity, having sufficient strength forsupporting articles of various weights and being of a metal similar tothe metal of the article being anodized.

The metals which are suitable for anodization are generally limited toaluminum, titanium, zirconium, tantalum and metals of that family. Thus,the supporting rack structure should be made from one of these metals inorder to preclude the use of dissimilar metals in the anodizing acidbath.

Rack structures made from aluminum have been known. However, aluminumdoes not provide the desired electrical contact and article holdingability due to its basic softness. In contrast, titanium metal racks arestrong and provide sufficient capacity to assure adequate currentdensity to anodize substantial numbers of individual parts held thereby.Because of its high corrosion resistance and the highly corrosiveenvironment of its operation, the use of titanium is highly desirable,if not imperative, in certain circumstances. Titanium racks are littleaffected by the chemical baths into which they must be immersed andsince they are so resistant to deterioration, consistent tensions andelectrical contact may be maintained throughout the anodization runs.Another disadvantage of aluminum racks is that they become coated with alayer of the anodic oxide with the result that their current carryingcapacity is markedly reduced. To render them usable thereafter, theracks must be stripped of their oXide coating by frequent strippingsolutions and treatment. Since such treatments areerrtremely'detrimental to the racks, they have a rela- 3,176,856Patented Apr. 6, 1965 tively short life. Titanium, on the other hand,has no such current resisting property and thus does not need repetitivestripping treatments. However, although titanium is most preferred,prior racks utilized entirely too much metal to make the the use oftitanium economically feasible. 1 v

The principal object of th s invention is to provide a structure foranodizing racks which is made from the ideal, but expensive, metaltitanium and which is more economically manufactured than prior artstructures.

Another object of the invention is to provide an anodizing rackcomprising an article holding disc having a plurality of radiallyextending fingers thereon of uniform elasticity with. the grain in themetal extending longitudinally of each finger thereby insuring a minimumof metal fatigue from repeated bending and flexingoperations andinsuring uniform article holding ability.

Still another object is to provide an article holding disc of the abovecharacter which is devoid of any cavities or compartments which couldtrap liquids therein and contaminate other baths when the holding discis removed from one bath for transfer to another.

A further object is to provide a simple and reliable clamping structurewhich is permanently secured to the central portion of the holding discand which is adjustable to securely clamp the disc at any desiredlocation on an elongated bar structure which during the anodizingprocess is normally vertically immersed in the said baths. V

- A related feature is concerned with the arrangement wherein the notedpermanent securemen't of the clamp to the holding disc performs aconstruction function for the disc member.

Other related features are concerned with notching the central portionof the disc to enable the entry of a clamp adjusting tool for adjustingthe position of the disc on the noted bar structure without interferingwith objects mounted in the rack, and is concerned also witharrangements for providing tabs on the clamp to permit the clampingoperation to be accomplished with a single fastener without anyundesirable tilting movement of the disc. r

Heretofore, holding discs, such as disclosed in my noted US. Patent No.3,033,776, consisted of a circular stamping having a plurality ofradially extending fingers integral therewith. This circular stampingnecessitated the use of titanium stock of dimensions at least thediameter of the disc being fabricated, resulting in substantial amountsof expensive titanium being scrapped. According to the presentinvention, a novel method of fabricating the disc is disclosed in whichrectangular stock material is still used but with the only scrapproduced being limited to the material removed informing slots betweenthe fingers which during the stamping operation are formed parallel toone another. Accordingly, it is another object of the invention toprovide a novel method of manufacturing the holding disc which resultsin a substantial reduction in scrap material over other known methods.

Additionally, the central area of known holding discs utilizes asubstantial amount of material which, if eliminated during manufacture,would appreciably reduce the cost of the discs made from titanium. It isaccordingly another object of the invention to provide a novel method ofmanufacturing thenoted holding disc in the general shape of an annuluwithout the material normally lo.- cated within the central area beingscrapped.

A still further object is to provide a method of manufacturing theholding disc from a rectangular piece of stock which is thereafter bentinto a circular form and permanently maintained in its circular form bya welding operation which also holds a clamping bracket for the disc,thereby simplifying the manufacturing steps.

With the foregoing and other objects in view, as will appear as thedescription proceeds, the invention consists of certain features ofconstruction, arrangement and a combination of parts and steps of themethod hereinafter fully described, illustrated in the accompanyingdrawings, and particularly pointed out in the appended claims, it beingunderstood that various changes in the form, proportion, size and minordetails of the structure may be made without departing from the spiritor sacrificing any of the advantages of the invention.

Referring now to the drawings:

FIG. 1 is a perspective view of a complete rack structure having twopair of my novel discs thereon for use in supporting different kinds ofarticles, one such article being shown in phantom view supported betweenjuxtaposed fingers of a pair of discs;

FIG. 2 is an enlarged perspective view of one of the holding discsconstructed according to the invention with portions broken away;

FIG. 3is an enlarged fragmentary view of a clamping bracket combinationutilizing a single fastener and a pair of projecting tabs for rigidly,but adjustably, securing the disc to the vertical supporting bar orstandard;

- FIGS. 4 and 5 are perspective views of the holding disc intwodifferent stages of manufacture; and

FIG. 6 is an exploded view of the holding disc before the various partsare finally assembled, with directional arrows indicating the movementsto be effected in completing the final assembly.

Referring now to FIG. 1, there is illustrated an anodizing rackdesignated generally by the reference character 10. The rack is adaptedto be hung from an overhead bus bar or the like and suspended in achemical anodizing bath contained within a tank or cell. The rack may bestationary or may be moved by means of a conveyorized moving belt orhook-like arrangement. The lining of the tank is usually the-cathode ofthe cell and the rack with the articles secured thereto is usually theanode for such cell.

The hook member 12, which is shown in broken outline, is an example ofmany different supporting means available to suspend the rack in thechemical bath. The entire rack is preferably formed of titanium metal,but such other metals as aluminum, tantalum, zirconium and others ofthis family and their alloys may be also advantageously used. The hookmember 12 may be made of other than the material comprising the rackmember 10, however, if so, said material must be conductive and must notbe immersed in the chemical anodizing bath.

The rack comprises a vertically disposed slotted bar member or standard14 of substantially polygonal crosssection, the particular configurationshown in FIGS. 1 and 3 being rectangular. Member 14 is preferably madeof titanium.

The rack 10 of FIG. 1 is made up of two pairs of holding discs allmounted on slotted member 14 of the rack. The discs of FIG. 1 aredesignated'as pairs 22A and 22B, and 24A and 24B, the upper disc of eachpair being characterized by the letter A and the lower member by theletter B. All of the discs have substantially the same configuration andmetal grain direction, but it is to be understoodthat variations in thespecific finger configurations are within the scope of this invention.

The discs are used in pairs with the fingers of each pair aligned tocooperate to hold articles either in compression or tension, one suchbeing shown in phantom outline. The disc pairs are illustrated in FIG. 1to hold articles by compression between corresponding fingers onadjacent discs of any pair but a simple reversal of the discs ofeitherpair will hold articles by tension exerted by the corresponding fingerson adjacent discs of any pair.

The discs are slidable and may be spaced at varying points along thelength of bar 14 so as to accommodate varying lengths of articles on thesame rack.

Referring now to FIG. 2 of the drawings, a more detailed description ofthe novel disc will be given.

The disc of FIG. 2, as seen from the top (a relative direction), is ofannular configuration with the inner periphery 21 comprising acylindrical sleeve terminating in a plurality of radially extendingfingers 23. The fingers 23 extend axially with the cylindrical sleeve 21a short distance and then are bent angularly to generally define a fiatfrusto-conical surface. The extremities or tips 25 of the fingers 23 arefurther bent to define the outer periphery of the annular shaped discand are notched at 25' to provide bifurcated sections to enhance theholding of articles. Various other types of tips may be provided. Theoverall disc is of a generally open-center dish-like configuration withthe dept-h and diameter being a matter of choice with the user. The opencircular area in the center of the disc permits free circulation of thechemical bath in addition to reducing the amount of material used.

A pair of clamp brackets 26A and 26B are shown in FIG. 2 positionedwithin the confines of sleeve 21. Each bracket is generally C-shapedwith the center portion thereof defining a straight section, such as 27Aand 27B- as best shown in FIG. 6. When the brackets 26A and 26B arepositioned back to back as shown in FIG. 2, the sections 27A and 27B areparallel and juxtaposed one to the other and are spaced apart a distanceapproximately equal to the thickness of slotted bar 14. The ends of eachbracket are curved and of a radius substantially the same as sleeve 21.The four curved ends 40A, 41A, 40B and 41B are spaced approximatelydegrees apart and are secured to the sleeve 21-by any suitable means,such as Welding as shown at 43. The angular positioning of these curvedends with respect to each other is a matter of choice as long assufiicient rigidity is provided. However, one curved end such as 40Bshould be positioned such that when welded to sleeve 21 it will securethe two ends of the sleeve 21 in abutting relation with each other asshown for sleeve ends 21A and 21B of FIGS. 3 and 6. The butt joint soformed is designated 44.

The straight section of at least one of the brackets 26A and 26B has apair of tabs 28 formed therein and arranged to engage outside the edgesof bar 14 when the discs are positioned thereon. These tabs 28 functionto seat and maintain the disc such as 22A normal to the slotted bar 14at all times.

A pair of threaded bolts 29 pass through corresponding and alignedapertures in the straight sections 27A and 27B of the brackets and incooperation with clamp members 3t) and 31 securely clamp the brackets26A and 26B against the face of slotted bar 14. The member 31 may beprovided with tapped holes to receive the threaded bolts 29. Thebrackets 26A and 26B are originally spaced apart to permit free movementalong bar 14 but'are of sufiicient resiliency to provide a reliableclamping action when bolts 29 are tightened. The bolt apertures in thestraight sections of the brackets 26A and 26B are shown spaced apart apredetermined distance so that they perform the same anti-tilt functionas tabs 28.

Since the bolts 29 are positioned within the confines of thefrusto-conical configuration, an adjusting tool normally might have tobe used at an angle to adjust the bolts. This disadvantage is overcomeby providing cutouts or notches, such as 32 and 33, on edges of sleeve21 which are seen most clearly in FIGS. 4 and 5. These notches areangularly spaced about the periphery of sleeve 21 so that an adjustingtool passes freely between the associated fingers 23. While only onepair of notches is needed, two pairs are provided so that the curved endof the bracket, being used to secure the two ends 21A and 21B of sleeve21 in abutting relation, can be secured thereto in either of its twopossible positions.

Referring now to FIG. 3, a slightly diiferent bolt arrangement isdisclosed. Since bar 14 is slotted, a singlebolt34- and nut 35 may beused in place of the two bolts and thick bar members of FIG. 2. Bolt 34passes through the slot on bar 14 to securely clamp the brackets theretoand the lugs or tabs 2% provide the seating function. This clampingembodiment is more economical than that shown in FIG. 2. Only one edgenotch equivalent to the pairs 32 and 33 is needed here. 7

FIGS. 4, 5 and 6 show the discs, such as 22A and 22B, in various stagesof manufacture. A piece of titanium flat stock, rectangular in shape andpreferably having the metal grain extending transversely thereof isused. As best seen in FIG. 5, the fingers 23 iare'formed by stamping outa small strip of metal between each finger to define the slots 36, thestampings being carried out one at a time or in multiple. At this stageof operations, the notches 32 and 33 may be formed. All of thesestampings take place while the stock is fiat material.

, The fiat stamping is then placed in a conventional sheet metal brakeand the sleeve portion 21 and finger tips 25 are formed in one or moresteps as shown in FIG. 4. It is to be noted that the bend 56 forming thesleeve 21' includes a portion 37 of the slots 36. As hereinbeforepointed out, the slotted portions as automatically provide drainageoutlets for the anodizing solutions when the rack is transferred fromone cell of the chemical bath to another. The particular configurationshown in FIG. 4 could be formed in one step as by a forming die orsimilar tools. Also, the sleeve section 21 could be bent in a directionopposite to the free ends 25.

The generally channel-shaped configuration shown in FIG. 5 is thenformed in its final shape by bending sleeve 21 in a circle as shown inFIG. 6 about axis 51 with the fingers radially extending therefrom. Theends 21A and 21B are brought into aligned abutting relation with eachother by moving them in the direction indicated by arrows 52 andbrackets 26A and 26B are positioned within the confines of sleeve 21 andwelded in place. The curved end such as dilB of one of the brackets isinitially positioned to overlap the abutted ends 21A and 21B and severalpoints on each of the latter ends are spot welded as at 43 to thepositioned bracket end. This secures the circular configuration of thesleeve 21, forming the butt joint 44. Thereafter, the other end 41B ofthe said bracket 26B is welded in position, followed by the welding ofthe other bracket 26A to sleeve 21 to define the parallel straightsections 27A and 27B adapted to engage the aces of slotted bar 14.

The assembled disc 22A is thus fabricated from a minimum of material andis formed in its final configuration with a minimum of operations. Theutilization of the curved end of one bracket to hold the two ends or"the circularly shaped disc structure eliminates additional parts andmanufacturing steps. Also, the provision of a central opening, whilereducing the amount of material used, enhances the circulation of theanodizing solutions around the articles being anodized and the slot ends3''! provide maximum drainage between baths. l

While the invention is principally directed to-a structure useful in theanodizing process, it is equally applicable to the structures used inother processes wherein a simple and economical disc rack is utilizedand wherein a simple method of fabrication is followed.

It is believed that this invention, its mode of COIlStlIlC- tion andmethod of assembly, and many of its advantageous advantages should bereadily understood from the foregoing without further description, andit should also be manifest that, while a preferred embodiment of theinvention has been shown and described for illustrative purposes, thespecific details are nevertheless capable of wide variation within thepurview of this invention as defined in the appended claims.

What is desired to secure by Letters Patent of the United States is:

1. A holder for supporting articles in a chemical bath or the likeadapted to be mounted along the length of a bar extend therethrough,comprising an annular shaped unitary structure having an inner sleevesection terminating in the plurality of radially extending resilientfinger means with the extremities of said fingers'collectively definingthe outer periphery of said annular shaped struc ture, and adjustableclamping means fixedly secured to said sleeve section and disposedwithin the confines thereof for frictionally engaging said bar tosupport the said article holder in any desired location therealong.

2. A holder for supporting articles in a chemical bath or the likeadapted to be mounted along the length of a bar extending therethrough,comprising a series of generally U-shaped elements with each elementsucceeding the first being interconnected with a preceding element atone point and with the series of elements being formed into an annularconfiguration with the first element of said series in abutting relationwith the last element of said series, and clamping means secured to theinner periphery of said annular configuration for frictionally engagingsaid bar to support the said article holder in any desired locationtherealong, the said clamping means maintaining said first and said lastU-shaped elements in abutting relation.

3. A holder for supporting articles in a chemical bath or the likeadapted to be mounted along the length of a bar extending therethrough,comprising a unitary structure having an inner sleeve sectionterminating in a plurality of radially extending resilient finger means,each said finger being separated from adjacent fingers at the saidsleeve section by a narrow aperture and being angularly disposedrelative to said sleeve section to define a disc-like annular structurewith the said apertures entering partially into the edge of the sleevesection, and clamping means secured to said sleeve section for frictionally engaging said bar to support the said article holder in anydesired location therealong.

4. A holder for supporting articles in a chemical bath or thelikeadapted to be mounted along the length of a bar extending therethrough,comprising an annular unitary structure having an inner sleeve sectionterminating in a plurality of radially extending resilient finger means,a pair of substantially C-shaped clamping means positioned back to backa distance apart at least equal to the distance between one pair ofsides of said bar and fixedly secured to said sleeve section, with atleast one of said clamping means having protruding tab means thereinspaced a distance apart at least equal to the distance between anotherpair of sides of said bar, and tensioning means for frictionallyengaging said bar between said pair of clamping means and between saidtab means to support the said article holder in any desired locationalong said bar.

5. A holder for supporting articles in a chemical bath or the likeadapted to be mounted along the length of a bar extending therethrough,comprising an annular unitary structure having an inner sleeve sectionterminating in a plurality of spaced apart radially extending resilientfinger means, a pair of substantially C-shapecl clamping meanspositioned back to back a distance apart at least equal to the distancebetween one pair of sides of said bar and fixedly secured to said sleevesection, with at least one of said clamping means having a pair ofprojecting tab means therein spaced a distance apart at least equal to adistance between another pair of sides of said bar, and tool adjustabletensioning means for frictionally engaging said bar between said pair ofclamping means and between said tab means to support the said articleholder in any desired location along said bar, said sleeve sectionhaving aperture means located therein in alignment with said tooladjustable tensioning means and with the opening between a pair of saidspaced apart finger means.

6. A holder for supporting articles in a chemical bath or the likeadapted to be mounted along the length of a polygonal slotted barextending through said holder, 3

comprising an annular unitary structure having an inner sleeve sectionterminating in a plurality of radially extending resilient finger meanselasticity, a pair of substantially C-shaped clamping means positionedback to back a distance apart at least equal to the distance between onepair of sides of said bar and fixedly secured to same sleeve section,with at least one of said clamping means having a pair of projecting tabmeans therein spaced a distance apart at least equal to the distancebetween another pair of sides of said bar, and tensioning meansextending through the slotted portion of said bar for frictionallyengaging the said bar between said pair of clamping means andbetweensaid tab means to support the said article holder in any desiredlocation along said bar.

7. The method-of making a generally circular holder for supportingarticles in a chemical bath and said holder adapted to be mounted to astandard extending axially therethrough, comprising the steps of cuttingfrom an elongate flat sheet'metal member a comb-like structure having aseries of free-ended spaced apart fingers with the fingers extendingtransversely of the member to form the teeth of the comb-like structureand the remainder of the member being a strip portion extending along anedge of the length of the sheet metal member and forming the back of thecomb-like structure with all of the fingers commonly connectedtherealong; bending the fingers on an angle relative to said stripportion; forming the strip portion into a cylindrical ring ofpredetermined diameter whereby to spread the fingers in a radial arrayabout said ring; and securing the strip portion in said cylindrical ringconfiguration.

8. The method as claimed in claim 7 in which the sheet metal member isof predetermined length and in forming the same into said ring the endsof the strip portion are welded together, and which method includes thestep of securing standard clamping means within the formed ringsimultaneously with securing the strip portion in said configuration.

9. The method as claimed in claim 7 in which the fingers are bent on abend spaced from their connections with the strip member.

10. The method as claimed in claim 7 which additionally includes thestep of forming the free tips of the fingers into articles graspingconfiguration prior to forming the strip into a circular ring.

11. The method as claimed in claim 7 in which the elongate flat sheetmetal member has the grain thereof oriented transversely of the stripportion and substantially parallel with the length of the fingers.

12. The method of making an annular holder for supporting articles in achemical bath and the holder adaptedto be mounted to a vertical barextending axially through" the same and having clamping bracket meanssecured thereto for clamping the holder to the bar, which comprises thesteps of stamping from a-rectangular strip of flat sheet stock acomb-like structure having teeth and an elongate back, forming articleholding configurations on the free ends of the teeth, bending the teethon an angle relative to the back, forming the back into a cylindricalconfiguration with the ends abutting and Welding the clamping bracketmeans inside of said abutting ends to secure said cylindricalconfiguration while attaching said clamping bracket means thereto.

13. A holder of sheet metal for supporting articles immersed in achemical bath or the like and adapted to be secured to a standard andthe holder comprising an annular shaped structure having a centralcylindrical sleeve and means on the interior of the sleeve for securingthe holder to the standard, a plurality of radially outwardly extendingarticle supporting fingers secured to said sleeve, spacedcircumferentially therearound and the direction of the grain of themetal of said fingers being uniformly parallel with the lengths of saidfingers whereby to provide uniform resilience therein.

14. A holder as claimed in claim 13 in which the fingers and sleeve areintegral, with the fingers connected to one end of the sleeve.

15. Holder means for supporting articles in a chemical bath or the likeand having clamping means for mounting same frictionally secured alongthe length of a bar extending therethrough and at any desired locationalong the length of said bar; said holder means comprising a generallycircular holder having an inner sleeve section and terminating in aplurality of radially extending resilent fingers, said fingers havingthe extremities thereof bent and collectively defining the outerperiphery of said circular holder.

References Cited by the Examiner UNITED STATES PATENTS 897,015 8/08Richmond 211-117 2,639,003 5/53 Russell 29-455 2,999,802 9/61 Gault204-297 3,006,481 10/61 Gussack 211-117 3,031,746 5 62 Ciarleglio 29-4553,033,776 5/62 Rosner 204-297 CLAUDE A. LE ROY, Primary Examiner. FRANKL. ABBOTT, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,176,850 I April 6, 1965 Ernest B. Rosner It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 1, line 26, for "cathode" read cathodes 0 I e column 2 line 5strike out "the" first occurrence column 7, line 3, strike out"elasticity".

Signed and sealed this 17th day of August 1965.

(SEAL) Atlest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. A HOLDER FOR SUPPORTING ARTICLES IN A CHEMICAL BATH OR THE LIKEADAPTED TO BE MOUNTED ALONG THE LENGTH OF A BAR EXTEND THERETHROUGH,COMPRISING AN ANNULAR SHAPED UNITARY STRUCTURE HAVING AN INNER SLEEVESECTION TERMINATING IN THE PLURALITY OF RADIALLY EXTENDING RESILIENTFINGER MEANS WITH THE EXTREMITIES OF SAID FINGERS COLLECTIVELY DEFININGTHE OUTER PERIPHERY OF SAID ANNULAR SHAPED STRUCTURE, AND ADJUSTABLECLAMPING MEANS FIXEDLY SECURED TO SAID SLEEVE SECTION AND DISPOSEDWITHIN THE CONFINES THEREOF FORM FRICTIONALLY ENGAGING SAID BAR TOSUPPORT THE SAID ARTICLE HOLDER IN ANY DESIRED LOCATION THEREALONG.